This invention relates generally to multiple nozzle injection molding apparatus and more particularly to such apparatus wherein a number of nozzles extend from an elongated melt distribution manifold and each nozzle has an elongated mounting flange from which two locating and insulating bushings extend into the mold on opposite sides of the nozzle.
Injection molding apparatus having a number of heated nozzles extending from an elongated heated melt distribution manifold into a cooled mold are well known. As seen in U.S. Pat. No. 5,282,735 to Gellert which issued Feb. 1, 1994, in some applications the front end of the nozzle is located in the mold and the rear end of the nozzle is attached to the melt distribution manifold by being screwed into it. However, in most applications, it is necessary to locate both the front and rear ends of the nozzle in the mold to allow the melt distribution manifold to move slightly relative to the rear end of the nozzles to allow for heat expansion and contraction of the elongated melt distribution manifold. As shown for instance in U.S. Pat. No. 5,429,491 to Gellert which issued Jul. 4, 1995, this is usually achieved by the nozzle having an outer cylindrical collar portion which is either an integral part of the nozzle or removable and sits against a circular seat in the mold. However, these previous nozzles with a cylindrical collar portion have the disadvantage that the cylindrical collar portions prevent the pitch between adjacent nozzles or cavities along the elongated melt distribution manifold being reduced as much as desired.